Oh, I hope it's not an expensive repair and can be fixed rather quickly for you.
You just made me realize the one and only benefit of not having a garage: my car will never get locked inside one! (The flip side is that every time it snows, you have to clean off all the snow and ice from the car!!)
Luckily, I bought a new battery in December, and that was one of the smartest things I've done, with the extremely low temperatures we've had over the past 2 months (many times dropping below zero). But that car starts right up with my dandy new battery!!

(Since the car was purchased as "used", there was no way to tell how old the battery in it was. As a preventative measure and for my peace of mind, I bought a new battery.)